Numerical simulation on electrostatic alignment control of cellulose nano-fibrils in flow

The alignment process of the cellulose nano-fibrils (CNFs) in an alternating electric field and elongational flow is numerically simulated for the fabrication of strong cellulose filaments. The order parameter of CNFs in the flow channel is evaluated by solving the Smoluchowski equation for the orientation distribution function of the CNFs. The results show that CNF alignment in the electric field is enhanced with applied voltage because the electrostatic torque is dominant over the Brownian rotation. An optimal fibril length is shown to exist for electrostatic alignment coupled with elongational flow effect. (paper)